Revetments are placed on river banks and river bottoms or lake shorelines to prevent erosion of the riverbank or shore by the action of the water against the riverbank or shore. Sea walls are vertical structures for similarly protecting riverbanks or lake frontage by retaining the earth adjacent lakes or rivers to prevent erosion. Revetments and sea walls are well known but generally are difficult to install over irregular surfaces and are not sufficiently durable to withstand long term water action.
One type of revetment is disclosed in U.S. Pat. No. 4,227,829 to Landry wherein a flexible mat of cellular blocks are woven together by means of a nonabrasive plastic cable in two directions. The longitudinal cables are threaded through holes in cast cement blocks at a remote manufacturing location. The mats of cement blocks are then placed on a truck for delivery to an installation site and installed in sections by a crane fitted with a special weldment for installing each section. The Landry revetment requires a labor intensive stringing of cables through the blocks and installation of the extremely heavy preassembled mats by a crane with a special attachment for maintaining the mats in a spread position prior to installation.
Another approach to forming revetments is to interlock concrete blocks having interlocking elements which are assembled together on site. Interlocking concrete blocks rely primarily upon the weight of the block and the interlocking construction to hold the revetment in place. Interlocking concrete blocks are not well suited for covering an uneven surface and require that the surface be first leveled prior to installation of the interlocking blocks. The interlocking blocks also suffer from the disadvantage that they may be dislodged if ice forms on the surface of the water adjacent the revetment.
Prior revetment structures fail to provide a simple and effective method for assembling a revetment on site which is permanently interlocked, capable of withstanding long term water erosion and can not be dislodged by the formation of ice upon the revetment.
The present invention is directed to overcoming one or more of the problems set forth above.